Wiper system

ABSTRACT

The invention is based on a wiper system ( 10 ) having a mounting plate ( 12 ), on whose mounting plate tube ( 14 ) a wiper bearing ( 20 ) is disposed on one end and a cast part ( 16 ) is disposed on the other, and a first bearing housing ( 22 ) for a second drive shaft ( 26 ) and a second bearing housing ( 28 ) for a control shaft ( 30 ) of a four-bar lever linkage are integrated with the cast part, and the second drive shaft ( 26 ) is driven by a wiper motor ( 32 ) via a motor crank ( 36 ), a drive element ( 44 ), and a bearing rocker ( 46 ). It is proposed that the wiper motor ( 32 ) is disposed as a reversing motor on the passenger side, and its motor shaft ( 34 ) is disposed on the cast part ( 16 ) in the vicinity of the second drive shaft ( 26 ), between the second drive shaft ( 26 ) and the control shaft ( 30 ), and the drive element ( 44 ) is embodied as a coupling plate.

PRIOR ART

[0001] The invention is based on a wiper system as generically definedby the preamble to claim 1.

[0002] Motor vehicle wiper systems with more than one windshield wiperare secured with their wiper bearings directly or indirectly via amounting plate to the vehicle body. The mounting plate—or tubularmounting plate, if the wiper carrier also includes tubular hollowprofiles—includes a motor mounting plate that carries a wiper drivemechanism with a wiper motor. A power takeoff shaft of the wiper motor,via a motor crank and joint rods, drives further cranks, which aresolidly connected to a drive shaft for each wiper. The drive shafts aresupported in wiper bearings, whose bearing housings are disposed on theends of the mounting plate.

[0003] If two wipers that sweep in the same direction are provided onthe vehicle, then as a rule the wiper on the driver's side is driven bythe motor crank via a joint rod pivotably connected to it, and by afurther crank, while the wiper on the passenger side is driven via afour-bar lever linkage with a four-bar wiper lever. The four-bar leverlinkage, whose kinematics bring about a combined reciprocating-pivotingmotion of the wiper, adapts the swept field of the wiper to thetrapezoidal shape of the windshield. The four-bar lever linkage includesa drive lever, seated on a drive axle, and a connecting rod that ispivotably supported about a control shaft. The free ends of theconnecting rod and the drive lever are pivotably connected to a couplingelement, the four-bar wiper lever. For some applications, the drivelever is embodied as a transversely jointed linkage.

[0004] As a rule, the connecting rod and the drive lever are firmlyseated on the control shaft and the drive shaft, respectively, which areeach rotatably supported in a bearing, with spacing from one another, ina cast part of the mounting plate. The cast part is joined via amounting plate tube to a bearing housing of a wiper bearing on thepassenger side. As a rule, a motor mounting plate for receiving a wipermotor is secured to the mounting plate tube.

[0005] The wipers are driven either by a revolving or a reversing wipermotor; either one wiper motor can be assigned to each wiper, or onewiper motor can drive a plurality of wipers in common. From GermanPatent Disclosure DE 199 34 869 A1, a wiper drive mechanism with areversing wiper motor is known, in which the semicircular driving motionof the motor crank is transmitted to the drive elements of the wipersvia a coupling gear. For driving the wiper on the passenger side, thecoupling gear is connected via a joint rod to the transversely jointedlinkage of a four-bar lever linkage, whose drive shaft and control shaftare supported in a part of the mounting plate, while the wiper on thedriver's side is driven via a further joint rod. The joint rods areconnected to the coupling gear by means of ball joints, whose ball pegsare disposed coaxially or axially parallel. The wiper motor is securedto the mounting plate via the wiper on the driver's side and the wiperon the passenger side.

[0006] A further wiper system is known from German Patent Disclosure DE199 40 815 A1, in which a first joint rod is pivotably connected to themotor crank and is connected via a crank to a first drive shaft for thewiper on the driver's side. Spaced apart from the joint at the motorcrank, a further joint for a second joint rod is provided on the firstjoint rod. The free end of the second joint rod is connected for drivingpurposes to a second drive shaft for the wiper on the passenger side viaa transversely jointed linkage. The pivotable connection point of thesecond joint shaft and the pivotable connection point at the crank arespaced apart from one another by a spacing that can be adapted to theconditions in the installation space.

ADVANTAGES OF THE INVENTION

[0007] According to the invention, the wiper motor is disposed as areversing motor on the passenger side, and its motor shaft is disposedbetween the second drive shaft and the control shaft on the cast part.The seat for the wiper motor and the two bearing housings for the driveshaft and the control shaft are integrated with the same cast part; as aresult, a separate motor mounting plate can be omitted, and an overallcompact structure of the mounting plate is obtained. Moreover, the motorshaft of the wiper motor is disposed in the vicinity of the second driveshaft. The slight spacing, at favorable force attack angles, makes alarge power takeoff angle or wiping angle of over 115° possible at thedrive shaft, an angle that otherwise, given conventional couplingsquares and a wiper motor in the form of a revolving motor, necessitatesa complicated and expensive transversely jointed linkage. Moreover,between the motor crank and a bearing rocker that is solidly joined tothe second drive shaft, a relatively short drive element is the result.This drive element is embodied as a coupling plate and replaces theotherwise usual long joint rod, making the drive mechanism in thisregion very compact. Compact mechanisms have good kinematic properties,leading to a harmonious course of motion.

[0008] In a wiper system with two wiper motors, the other wiper isdriven separately by a further wiper motor; the two wiper motors arecoupled electrically to one another on the master-slave principle. Ifthe wiper system has only one wiper motor, then the wiper motor isdisposed on the passenger side and simultaneously drives a first driveshaft of a wiper on the driver's side. In that case, the motor crank isconnected via a first joint to a joint rod, which drives the first driveshaft via a crank and is connected to the coupling plate via a secondjoint. Depending on the installation space or kinematic conditions, thejoints can be disposed coaxially or axially parallel. In addition, bothjoints can also be disposed on the motor crank and have a spacing fromone another.

DRAWING

[0009] Further advantages will become apparent from the ensuingdescription of the drawing. In the drawing, exemplary embodiments of theinvention are shown. The drawing, description and claims includenumerous characteristics in combination. One skilled in the art willalso expediently consider the characteristics individually and put themtogether to make useful further combinations.

[0010] Shown are:

[0011]FIG. 1, a wiper system of the invention in a view from below, in aparked position;

[0012]FIG. 2, a wiper system of FIG. 1 at a turning-point position;

[0013]FIG. 3, a side view of the wiper system of FIG. 1;

[0014]FIG. 4, a variant of FIG. 1 in a view from below;

[0015]FIG. 5, a side view of a wiper system of FIG. 4;

[0016]FIG. 6, a wiper system in which each wiper is assigned its ownwiper motor; and

[0017]FIG. 7, a wiper system of FIG. 6 in a side view.

DESCRIPTION OF THE EXEMPLARY EMBODIMENTS

[0018] The parts essential to the invention of a wiper system 10 for twowipers are shown. A mounting plate 12 includes a mounting plate tube 14,which on one end carries a wiper bearing 20 for a first drive shaft 24and on the other end is joined to a cast part 16 (FIG. 1). A firstbearing housing 22 for a second drive shaft 26 and a second bearinghousing 28 for a control shaft 30 are disposed in the cast part 16. Adrive lever of a four-bar lever linkage, not shown, is secured in aknown manner to the drive shaft 26, while a connecting rod is seated onthe control shaft 30. Via fastening eyelets 18 on the wiper bearing 20and on the cast part 16, the mounting plate 12 is secured to a vehiclebody, not shown.

[0019] A wiper motor 32, embodied as a reversing motor, is secured tothe cast part 16, specifically in such a way that its motor shaft 34 isdisposed between the second drive shaft 26 and the control shaft 30; thespacing from the drive shaft 26 is less than from the control shaft 30.A motor crank 36 is seated on the motor shaft 34 and is connected to ajoint rod 50 via a first ball joint 38. A crank 48 is pivotablyconnected to the other end of the joint rod 50 and is connected to afirst drive shaft 24 for a wiper on the driver's side. In the region ofthe first ball joint 38, the joint rod 50 has a second ball joint 40, towhich a coupling plate 44 is pivotably connected. The coupling plate isconnected on its other end, via a third ball joint 42, to a bearingrocker 46, which is seated on the second drive shaft 26 for a wiper onthe passenger side.

[0020] The wiper motor 32 is of the reversing type, and the respectiveturning point positions are shown in FIG. 1 and FIG. 2. A comparison ofthese two drawings shows that a large power takeoff angle or wipingangle is created at the second drive shaft 26. As a result of this largepower takeoff angle and a four-bar lever linkage, not shown in detail,that is disposed following it, a desired reciprocating-pivoting motionis created without requiring additional linkage parts such as atransversely jointed linkage.

[0021] In an embodiment of the invention, the ball joints 38 and 40 aredisposed axially parallel in one plane on the joint rod 50 (FIG. 3). Thejoint 42 connects the coupling plate 44 to the bearing rocker 46 and isshown in this drawing as a cylinder joint. In the case of flat leverlinkages, it is also conceivable for the joint 38 or the joint 40 to bealso embodied as a cylinder joint. To create a different curve of motionof the pivot point 40 and thus an altered drive angle, the joints 38 and40, in one embodiment of the invention, are disposed on the motor crank36, for instance coaxially (FIG. 4, FIG. 5).

[0022] If the wiper system 10 has two wiper motors 32 that each areassigned to one wiper, then the motor shaft 34 of one wiper motor 32drives the second drive shaft 26 via the motor crank 36, the couplingplate 44, and the bearing rocker 46 (FIG. 6, FIG. 7). In that case,great freedom of design is obtained for the wiper system 10,particularly with a view to its kinematics and the disposition of itscomponent elements.

1. A wiper system (10) having a mounting plate (12), on whose mountingplate tube (14) a wiper bearing (20) is disposed on one end and a castpart (16) is disposed on the other, and a first bearing housing (22) fora second drive shaft (26) and a second bearing housing (28) for acontrol shaft (30) of a four-bar lever linkage are integrated with thecast part, and the second drive shaft (26) is driven by a wiper motor(32) via a motor crank (36), a drive element (44), and a bearing rocker(46), characterized in that the wiper motor (32) is disposed as areversing motor on the passenger side, and its motor shaft (34) isdisposed on the cast part (16) in the vicinity of the second drive shaft(26), between the second drive shaft (26) and the control shaft (30),and the drive element (44) is embodied as a coupling plate.
 2. The wipersystem (10) of claim 1, characterized in that it has two wiper motors(32), of which the motor shaft (34) of one wiper motor drives the seconddrive shaft (26), via the motor crank (36), the coupling plate (44), andthe bearing rocker (46), while the other wiper motor is associated withthe first drive shaft (24).
 3. The wiper system (10) of claim 1,characterized in that the motor crank (36) is connected via a firstjoint (38) to a joint rod (50), which drives the first drive shaft (24)via a crank (48), and is connected to the coupling plate (44) via asecond joint (40).
 4. The wiper system (10) of claim 3, characterized inthat the joints (38, 40) are disposed next to one another in the sameplane.
 5. The wiper system (10) of claim 3, characterized in that thejoints (38, 40) are disposed coaxially.
 6. The wiper system (10) ofclaim 1, characterized in that the motor crank (36) is connected via afirst joint (38) to a joint rod (50), which drives the first drive shaft(24) via a crank (48) and is connected to the coupling plate (44) via asecond joint (40).
 7. The wiper system (10) of one of claims 1-6,characterized in that at least one joint (38, 40) is embodied as a balljoint, and the others are embodied as cylinder joints.